login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A060189 A column and diagonal of A060187 (k=3). 2
1, 23, 230, 1682, 10543, 60657, 331612, 1756340, 9116141, 46702427, 237231970, 1198382694, 6031771195, 30287995733, 151856096504, 760614930344, 3807336276505, 19050241098975, 95294209168414, 476607030432890 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,2

LINKS

Table of n, a(n) for n=3..22.

P. A. MacMahon, The divisors of numbers, Proc. London Math. Soc., (2) 19 (1920), 305-340; Coll. Papers II, pp. 267-302.

Index entries for linear recurrences with constant coefficients, signature (14,-75,196,-263,174,-45).

FORMULA

a(n) = 5^(n-1) - n*3^(n-1) + n(n-1)/2. - Ralf Stephan, May 08 2004

G.f.: -x^3*(9*x^3+17*x^2-9*x-1) / ((x-1)^3*(3*x-1)^2*(5*x-1)). - Colin Barker, Dec 19 2012

From Wolfdieter Lang, Apr 17 2017: (Start)

a(n) = A060187(n, 3) , n >= 3 (and 0 for n = 0,1,2).

a(n) = A060187(n, n-2), n >= 3 (and 0 for n = 0,1,2).

E.g.f.: (2*exp(5*x) - 10*x*exp(3*x) + 5*x^2*exp(x) - 2)/10. (End)

CROSSREFS

Sequence in context: A124336 A010829 A022715 * A028824 A096983 A140572

Adjacent sequences:  A060186 A060187 A060188 * A060190 A060191 A060192

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, Mar 20 2001

EXTENSIONS

More terms from Vladeta Jovovic, Mar 20 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 19 08:54 EST 2018. Contains 299330 sequences. (Running on oeis4.)